Dental-mold unit.



C. A. NIXON.

DENTAL MOLD UNI-T APPLICATION FILED MAY a, 1916.

Patented Feb. 27,1917.

$71k, INVENTOR.

A TTORNE Y CLINTON A. NIXON, OF VALPARAISO, INDIANA.

DENTAL-MOLD UNIT.

Specification of Letters Patent.

Patented Feb.27, 1217.

Application filed May 8, 1916. Serial no. 96,190.-

paraiso, in the county of Porter and State.

of Indiana, have invented certain new and useful Improvements in Dental-Mold Units, of which the following is a specification.

My invention relates to improvements in dental mold units or flasks and it appertains in some of its adaptations to the exemplifications shown in the accompanying drawing and instanced in the description thereof.

Among the purposes of the invention there may be mentioned the production of unit flasks which are provided with means for re taining any pressure to which they have been subjected until the contents are set;to provide means for quickly opening the same so as to easily remove the content; and to provide duplicates for new work while the materials placed in prior molds is hardenmg.

With these and other ends in view I illustrate in the accompanying drawing such instances of adaptation as will disclose the fundamental features without limiting myself to the specific details shown.

Figure 1is a side elevation."

Fig. 2is an elevation in section.

Fig. 3-is a top plan view of Fig. 1;

Fig. 4.-is a top plan of the mold parts of Fig. 1 opened.

Fig. 5is a side elevation partly in section instancing a modified form of pressure retaining means.

Fig. 6is a top plan view of Fig. 5 with the plunger and sleeve removed.

The principal feature of my invention lies in the production of a sectional mold of any desired style or shape, in providing a follower or plunger that can be placed under a press so as to subject the contents of the mold to pressure, and in means adapted to hold the parts so as to not release the pres- 1 sure when the mold is removed from the press.

There are many forms -of presses specially designed for dentists uses. They have a suitable base, usually a crooked standard, a threaded stem in the standard and a hand wheel attached to the stem. The flasks are base. Heretofore a short tube closed at one 7 handled.

end hasbeen used. This necessitated leaving the mold. under the press until the contents became set.v

Molds are used by dentists to secure metal replicas of impressionsmade of cavities in a self-hardening molding composltlon. This forms a matrix lnto whichaplastic metal is worked and then placed under pressure until it hashad time to set. With sectional molds made as independent units many separate teeth can be undergoing the setting process without the continued use of an individual press for each mold, thus largely increasing the volume of work that can be The flask or mold instanced in Figs. 1 and Kris sectional, one half of it is designated by land 1 and the other half by 2 and 2 These halves taken together form an opening 10 that has a bottom 11'. 1 A followeror plunger '12 passes into the opening 10. It has a head 13 or 13 against which the threaded stem of a'press abuts. The parts 1 and 2, closed, rest against the baseof the press. The lower portion of the mold is filled with plaster or other compound 17. Into this the self-hardening impression 19 of a tooth cavity is placed. .These impressions are usually held in a metal ring or tube 19. Nithin the space betweenthe impression 19 and the top'of the plaster a-plastic metal 20 is placed and on top of this a rubber washer 21 rests. It is necessary thatthe material 20 be held in contact with the'impression 19 so that the smallest details will be reproduced.

. The plunger 12 presses against the rubber washer 21 thus holding the materials in closest contact. After this. pressure is secured by means of the usual press the plunger 12 may be held in place in any suitable manner. An exemplification of two methods is instanced, both accomplishing the same purpose. In the exemplification shown in Fig.1 the head 13 has projections 15 into which depending pins 14 are secured. These pins pass into holes 16 of the projections 3 formed at the top of each half of the mold. Thumb screws 9 threaded into such projections serve to clamp pins let in holes 16 and thus hold the plunger 12 in position so that none of the imparted pressure islost.

It is not material that the stems 14: are rigidly secured in ears 15 of the plunger head 13 and made to slide in ears 3 of the mold parts 1 and 2 and held by set screws 9, because these stems could be rigidly secured in the ears 3 so as to project upward and pass into openings of ears 15 of the plunger head 13 whereon set screws 9 could be used to clamp the stems. Such an alternative form would be an equivalent of the device shown in Figs. 1 and 2 and would be as fundamental to my invention as the structure shown in these figures, in fact the scope of the invention is such that any means of whatever order adapted to hold the plunger against the contents of the mold temporarily until the contents are set and allow the mold and plunger to be used as a separate unit independently of all others is a basic feature of my invention, whatever kind of fastening means are used.

The adaptation shown in Fi g. 6 comprises the two halves 1 and 2 of a mold having the same inner structure as Fig. 1. It has a flanged base 23, a threaded part 25 and a cylindrical guiding portion 26 for the sleeve 27. The plunger head 13 has a flange l5 against which the flange 29 of the sleeve 27 abuts. The sleeve is threaded so as to lead onto the threads 25 when it is turned by means of knurled flange 28 after the pressure has been applied to head 13 so as to hold tl e plunger in position against the washer 21, performing the same function as the pins 14- and set screws 9. If needed the flanges 23 and 28 may be made hexagon or other shape to assist in unscrewing the sleeve 27 or pin holes 24 and 30 may be used for this purpose.

After the plunger has been released on the completion of a cast the two halves of the mold can be separated by removing pin 7 from holes 6 shown in'Figs. 1 and 4 or prying them apart at the recess 31 shown in Fig. 6. The parts are pivoted on pin 8 and may interlock as shown at a, 5 and 22. By making the mold in parts the cast is easily removed and the units may be stacked into a compact space. If an individual press was used for each flask there would be little economy of space. It is of course obvious that pin 8 can be made removable if desired so as to completely separate the two mold halves.

The device is simple and compact and enables an operator to produce superior results in such volume as could not be attained without its aid.

l Vhat I claim is,

1. In unit dental molds, a sectional open ended chamber, a plunger movable therein, and means carried by the sectional chamber adapted to temporarily hold the plunger against displacement.

2. In unit dental molds,.a mold chamber adapted to be opened to release its contents, an independent part of said unit adapted to confine the contents within the mold under pressure, and retaining means carried by said mold parts whereby said independent part may be temporarily rigidly held against displacement.

3. A hinged two-part unit mold, means for holding the same closed, a plunger movable therein constituting a pressure retaining device complete for each unit carried by the mold, and means adapted to rigidly hold the same against displacement suffciently long to complete the treatment of the contents of the mold.

4. A suitable sectional unit mold comprising inclosed sides and bottom, a structurally cooperative closure therefor adapted to engage the contents of the mold, and means for temporarily holding the closure against displacement such means forming a part of the unit mold.

5. A two-part mold, a threaded exterior, a plunger operable therein, and a sleeve adapted to hold the plunger at predetermined positions in the mold.

6. A sectional dental mold, a plunger operable therein, and separate'means en circling the plunger and mold adapted to hold the parts in assembled relation as an independent unit. r

7 In dental molds a pair of hinged members forming an open ended chamber when they are closed, a plunger operable through the open end, means on each hinged member cooperating with the plunger adapted to temporarily hold the latter against displacement and permit the use of the unit independently of other units.

In testimony whereof I aflix my signature in presence of two witnesses.

CLINTON A. NIXON. Witnesses Mrs. F. A. KRoE'rz, A. L. AMs'rU'rz.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

